The [3 + 3] annulation of α,β-unsaturated aldehydes with 2-substituted 1,4-naphthoquinones allowing the facile synthesis of functionalized dihydrocoumarins catalyzed by N-heterocyclic carbene (NHC) is reported. The initially formed NHC-homoenolates underwent an efficient Michael–isomerization–lactonization cascade to furnish the products. Preliminary studies on mechanism shed light on the homoenolate
据报道,α,β-不饱和醛与 2-取代的
1,4-萘醌的 [3 + 3] 环化可以轻松合成由 N-杂环卡宾 (NHC) 催化的功能化二氢
香豆素。最初形成的 NHC-homoenolates 经历了有效的迈克尔 - 异构化 - 内酯化级联以提供产品。对机制的初步研究揭示了 α,β-不饱和酰基唑中间体中间体的同烯醇化物途径。此外,使用手性 NHC,所需产物的产率高达 49%,比价为 99:1。